Very Hot Drinks Could Raise Oesophageal Cancer Risk, New Research Suggests

A steaming cup of tea or coffee is a daily comfort for millions of people. However, new research suggests that regularly drinking beverages at extremely high temperatures could increase the risk of developing cancer of the oesophagus, also known as the food pipe.

Researchers from the University of Oxford have found a possible association between consuming very hot drinks and an increased risk of oesophageal cancer. The study involved almost one million middle-aged men and women, making it one of the largest investigations into the relationship between beverage temperature and this type of cancer.

The findings suggest that people who regularly drank tea or coffee classified as "very hot" had approximately three times the risk of developing oesophageal cancer compared with those who drank their beverages at warmer temperatures.

Despite this increase in relative risk, experts emphasise that oesophageal cancer remains uncommon. Drinking a very hot beverage does not mean that a person will develop cancer, and there are several other lifestyle factors that have a much stronger influence on cancer risk.

How hot is too hot?

The Oxford research classified drinks at temperatures of 65°C or higher as "very hot". At these temperatures, beverages can be uncomfortable or even painful to drink, but some people may still consume them shortly after preparation.

A freshly boiled kettle can heat water to around 100°C. When that water is used to make tea or coffee, the temperature may initially remain around 90°C to 95°C. Although pouring the drink into a cup and adding milk can reduce the temperature, the beverage may still be considerably hotter than the level considered potentially concerning in the research.

For people who enjoy hot drinks, one simple approach is to allow the beverage to cool naturally before taking a sip.

Cancer Research UK advises people who are concerned about the temperature of their drinks to wait until the beverage feels comfortable to drink rather than consuming it while it is still extremely hot.

There is no universally agreed waiting time because the speed at which a drink cools depends on several factors, including the size and material of the cup, the amount of liquid, the surrounding temperature and whether milk has been added.

Why could very hot drinks be harmful?

The researchers believe repeated exposure to very hot liquids may damage the cells lining the oesophagus.

The oesophagus carries food and drinks from the mouth to the stomach. When extremely hot liquid passes through it, the heat can cause irritation or injury to the tissue.

Repeated damage may contribute to changes in cells over many years. These changes could potentially increase the likelihood of abnormal cells developing and eventually becoming cancerous.

The theory is not entirely new. Previous research has examined the possible connection between very hot beverages and oesophageal cancer in regions where people traditionally consume drinks at extremely high temperatures.

One example is South America, where a herbal drink known as mate is commonly consumed. Some studies in populations that regularly drink very hot mate have also reported an association with oesophageal cancer.

Lead researcher Dr Keren Papier said that further research is needed to determine more precisely which drink temperatures are associated with increased risk.

This is important because people often describe a drink as "hot" or "very hot" based on personal preference. What feels extremely hot to one person may be considered comfortable by another.

The number of drinks may also matter

The research also identified a relationship between the number of hot drinks consumed and cancer risk.

People who consumed six or more hot drinks each day appeared to have a higher risk than those who consumed fewer. However, it is important not to interpret this as meaning that drinking six cups of tea or coffee automatically causes cancer.

The research examines patterns and associations within a large population. It does not prove that temperature alone is directly responsible for every case of oesophageal cancer.

Other characteristics and lifestyle habits can influence cancer risk, and researchers must consider these factors when interpreting the results.

What about coffee and tea from cafés?

Coffee served outside the home can sometimes be particularly hot. Some takeaway coffee manufacturers recommend serving temperatures around 49°C to 60°C, although drinks can be served substantially hotter when customers request an extra-hot beverage.

A separate study involving 118 young adults investigated people's preferences for different coffee temperatures. Researchers found that many participants considered coffee too hot when its temperature reached approximately 70°C or above.

This suggests that allowing a drink to cool slightly may not only reduce potential exposure to damaging temperatures but may also make it more comfortable to consume.

Adding milk can lower the temperature, but it does not necessarily make a freshly prepared drink cool enough immediately. A milky tea or coffee can still be very hot.

The overall cancer risk remains relatively small

The findings may sound alarming, particularly because the study found an approximately threefold difference in risk between very hot and warm beverage drinkers. However, relative risk needs to be considered alongside the underlying likelihood of developing the disease.

Oesophageal cancer is relatively uncommon. Researchers estimate that roughly one or two out of every ten cases of oesophageal cancer could potentially be prevented if people stopped consuming beverages at extremely high temperatures.

The researchers also point out that other established risk factors are more important when considering ways to reduce the risk of oesophageal cancer.

Smoking and excessive alcohol consumption are among the major factors associated with the disease. Reducing or avoiding these exposures remains much more important than worrying about an occasional hot cup of tea or coffee.

What can people do?

For most people, there is no need to stop drinking tea, coffee or other hot beverages.

Instead, the practical advice is simple: let very hot drinks cool before drinking them.

If a beverage has just been made with boiling water and is producing a large amount of steam, waiting a few minutes can make a significant difference. Taking a small sip first can also help determine whether the temperature is comfortable.

People should also pay attention to persistent symptoms that could indicate a problem with the oesophagus. These can include ongoing heartburn, difficulty swallowing, indigestion, unexplained weight loss or persistent pain in the throat or chest.

Having one of these symptoms does not necessarily mean someone has cancer, as many common conditions can cause similar problems. However, persistent or unexplained symptoms should be discussed with a healthcare professional.

The new research adds to growing evidence that the temperature of beverages may matter, particularly when very hot drinks are consumed regularly over a long period.

For tea and coffee lovers, the message is therefore not to panic. A simple pause before drinking could reduce exposure to potentially harmful temperatures, while established measures such as avoiding smoking and limiting alcohol remain among the most important ways to lower oesophageal cancer risk.

Sources: BBC News, Cancer Research UK, University of Oxford researchers, the International Journal of Cancer, and research published in Scientific Reports.

Disclaimer: This article is for general informational purposes only and is based on the research and reporting available in the source material. It does not provide medical advice or establish that drinking very hot beverages directly causes cancer. Individual health risks can vary. Anyone experiencing persistent or concerning symptoms should speak with a qualified healthcare professional.